Hemodialysis requires anticoagulants to prevent fibrin deposition and thrombus formation in the extracorporeal circuit. Unfractionated heparin (UFH) has been used as a conventional anticoagulant for a long time. But recently, many side effects of heparin have been documented: hemorrhage, thrombocyto- penia with or without thrombosis, osteoporosis, skin necrosis, alopecia, and hypersensitivity reactions. In the past decade, low molecular weight heparins (LMWH) have been developed. Compared with UFH, these compounds have a longer plasma half life, less variability in the anticoagulant response to fixed doses, and a more favorable antithrombotic to hem- orrhagic ratio. Thus, rationales for using LMWH as an altemative to UFH would be a reduced risk of bleeding complications and simplified routines for heparinization due to a longer half-life of the anti- coagulant activity. To evaluate the efficacy and safety of LMWH as an anticoagulant in hemo- dialysis treatment, we conducted a prospective cross- over study with paired comparison of two different heparins in 18 end-stage renal disease patients undergoing hemodiatysis. During the first two months of observation, patients received a single bolus of LMWH (Fragmin) 2,552±221 aXa IU/one dialy- sis session, Then patients were switched to UFH dose regimen comprised of a saline prime, no initial bolus and a continuous infusion of 3,174±420 IU/one dialysis session for further two months. All hemodialysis sessions were completed uneventfully. The coagulation values of an anti-factor Xa-specific clotting method (Heptest) from citrated whole blood samples taken 15 minutes after starting hemodialysis were 0.47±0.21 U/ml with LMWH and 0.12±0.03 U/ml with UFH 0.05). The prolongation of the Heptest clotting times with LMWH and UFH was 2.86 for LMWH and 2.55 for UFH using the whole blood assay. The mean frequency of clot deposition in dialyzer was similar (1.1 vs 0.87) as well as mean venous compression time at the end of dialysis (5.96 vs 6.23 minutes). The hematologic and biochemical parameters such as hemoglobin, platelet count, triglyceride level, total cholesterol and HDL-cholesterol level did not show any differences between the two heparins. We conclude that a single dose of LMWH is effective and safe in repeated use for hemodialysis and prevents clot formation to a similar degree as UFH. |